A portal application is a tool that aggregates information from diverse sources onto a page for quick access by a user. Generally this information is displayed to the user through a collection of portlets, which are autonomous user interface software components that can be embedded into a page displayed by the portal application. For example, a portal application may display an email portlet which communicates with an email server and displays recent email messages to the user, a calendar portlet which communicates with a calendar server and displays the user's calendar to the user, a news portlet which communicates with one or more news servers to display a list of headlines to the user, and a weather portlet which communicates with a weather server to display a current weather forecast to the user.
Portal applications are widely popular with corporations and other large entities. For example, many corporate intranets offer a large selection of information accessible to employees, and customized portlets may be used to deliver this information to the employees logging onto the intranet. Through the use of a portal application, the content from the corporate intranet that is presented to a particular employee logging on to the intranet may be customized based on the employee's position and/or personal preferences.
The inherent advantages of portal applications, together with the increasing availability and popularity of internet-enabled mobile devices, have led to a burgeoning demand for portal applications that are accessible on mobile, battery-powered devices. However, because many of the portlets available through such portal applications rely on data connections to the internet and/or other networks to function properly, portal applications can lead to heavy consumption of battery power in mobile devices. This consumption may shorten the usable life of a mobile device between battery charges.